Well, the <database>.mdf file is
the database and all it contains. The .ldf is the log file.
If the data was properly detached from the source server, then all you need to do is place it within reach of the target server and re-attach it. YOu don't need the log file, as a new one will be re-created.
The easiest way is to use Enterprise Manager, click on the server, then right click 'Databases', 'All Tasks', then 'Attach Database...', then point to the mdf file.
You can also use the 'sp_attach_single_file_db' system stored procedure to attach from Query Analyzer.
Custom Apps, Inc.